This paper proposes a fractional-order simplest chaotic system using a bi-stable locally-active memristor.The characteristics of the memristor and transient transition behaviors of the proposed system are analyzed,and...This paper proposes a fractional-order simplest chaotic system using a bi-stable locally-active memristor.The characteristics of the memristor and transient transition behaviors of the proposed system are analyzed,and this circuit is implemented digitally using ARM-based MCU.Firstly,the mathematical model of the memristor is designed,which is nonvolatile,locally-active and bi-stable.Secondly,the asymptotical stability of the fractional-order memristive chaotic system is investigated and some sufficient conditions of the stability are obtained.Thirdly,complex dynamics of the novel system are analyzed using phase diagram,Lyapunov exponential spectrum,bifurcation diagram,basin of attractor,and coexisting bifurcation,coexisting attractors are observed.All of these results indicate that this simple system contains the abundant dynamic characteristics.Moreover,transient transition behaviors of the system are analyzed,and it is found that the behaviors of transient chaotic and transient period transition alternately occur.Finally,the hardware implementation of the fractional-order bi-stable locally-active memristive chaotic system using ARM-based STM32F750 is carried out to verify the numerical simulation results.展开更多
The self-excited attractors and hidden attractors in a memcapacitive system which has three elements are studied in this paper.The critical parameter of stable and unstable states is calculated by identifying the eige...The self-excited attractors and hidden attractors in a memcapacitive system which has three elements are studied in this paper.The critical parameter of stable and unstable states is calculated by identifying the eigenvalues of Jacobian matrix.Besides,complex dynamical behaviors are investigated in the system,such as coexisting attractors,hidden attractors,coexisting bifurcation modes,intermittent chaos,and multistability.From the theoretical analyses and numerical simulations,it is found that there are four different kinds of transient transition behaviors in the memcapacitive system.Finally,field programmable gate array(FPGA)is used to implement the proposed chaotic system.展开更多
We report the fabrication and photocarrier dynamics in graphene–MoSe2 heterostructures. The samples were fabricated by mechanical exfoliation and manual stacking techniques. Ultrafast laser measurements were performe...We report the fabrication and photocarrier dynamics in graphene–MoSe2 heterostructures. The samples were fabricated by mechanical exfoliation and manual stacking techniques. Ultrafast laser measurements were performed on the heterostructure and MoSe2 monolayer samples. By comparing the results, we conclude that photocarriers injected in MoSe2 of the heterostructure transfer to graphene on an ultrafast time scale. The carriers in graphene alter the optical absorption coefficient of MoSe2. These results illustrate the potential applications of this material in optoelectronic devices.展开更多
文摘This paper proposes a fractional-order simplest chaotic system using a bi-stable locally-active memristor.The characteristics of the memristor and transient transition behaviors of the proposed system are analyzed,and this circuit is implemented digitally using ARM-based MCU.Firstly,the mathematical model of the memristor is designed,which is nonvolatile,locally-active and bi-stable.Secondly,the asymptotical stability of the fractional-order memristive chaotic system is investigated and some sufficient conditions of the stability are obtained.Thirdly,complex dynamics of the novel system are analyzed using phase diagram,Lyapunov exponential spectrum,bifurcation diagram,basin of attractor,and coexisting bifurcation,coexisting attractors are observed.All of these results indicate that this simple system contains the abundant dynamic characteristics.Moreover,transient transition behaviors of the system are analyzed,and it is found that the behaviors of transient chaotic and transient period transition alternately occur.Finally,the hardware implementation of the fractional-order bi-stable locally-active memristive chaotic system using ARM-based STM32F750 is carried out to verify the numerical simulation results.
基金Project supported by the National Natural Science Foundation of China(Grant No.51377124)the Science Fund for New Star of Youth Science and Technology of Shaanxi Province,China(Grant No.2016KJXX-40).
文摘The self-excited attractors and hidden attractors in a memcapacitive system which has three elements are studied in this paper.The critical parameter of stable and unstable states is calculated by identifying the eigenvalues of Jacobian matrix.Besides,complex dynamical behaviors are investigated in the system,such as coexisting attractors,hidden attractors,coexisting bifurcation modes,intermittent chaos,and multistability.From the theoretical analyses and numerical simulations,it is found that there are four different kinds of transient transition behaviors in the memcapacitive system.Finally,field programmable gate array(FPGA)is used to implement the proposed chaotic system.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61275058,61527817,61335006,and 61378073)the National Science Foundation,China(Grant No.DMR-1505852)+1 种基金the National Basic Research Program of China(Grant Nos.2016YFA0202300 and 2016YFA0202302)Beijing Science and Technology Committee,China(Grant No.Z151100003315006)
文摘We report the fabrication and photocarrier dynamics in graphene–MoSe2 heterostructures. The samples were fabricated by mechanical exfoliation and manual stacking techniques. Ultrafast laser measurements were performed on the heterostructure and MoSe2 monolayer samples. By comparing the results, we conclude that photocarriers injected in MoSe2 of the heterostructure transfer to graphene on an ultrafast time scale. The carriers in graphene alter the optical absorption coefficient of MoSe2. These results illustrate the potential applications of this material in optoelectronic devices.